Descritores químicos e sensoriais para discriminação da qualidade da bebida de café arábica de diferentes genótipos e métodos de processamento

Abstract

The impacts of different ways of producing coffee on the beverage quality have been debated for years and will surely continue to be studied in the next decades, mainly because it is a phenomenon of high complexity. Crop season, altitude, slope exposure, fruit color, genotype, processing method, as well as the chemical composition of green coffee and its relation with the sensory quality will be addressed in this study to answer one of the most frequent questions in the consumer market: what are the reasons for coffee quality? Therefore, an initial study was developed to characterize the quality from the sensorial descriptors of coffee. During the 2010 and 2011 crop seasons, it was analyzed the sensorial quality of varieties of red and yellow fruit (Coffea arabica L.) cultivated in environments with different slopes exposure and altitude between 932 m and 1,391 m. Based on the results found in the first study, two new studies were developed for the 2010, 2011, and 2012 crop seasons, aiming to characterize the profile of organic acids associated with bioactives and also the profile of fatty acids present in green coffee. It was also investigated the potential of these chemical groups in discriminating the sensorial quality of coffee, comparing the performance of the Yellow Bourbon and Acaiá genotypes submitted to both dry and wet processing methods (mechanically pulped and demucilaged coffee). All harvesting and post-harvesting procedures were performed according to the main technologies for the production of specialty coffees. The sensorial analyzes were performed using the methodology proposed by the American Association of Special Coffees (SCAA). The chemical analyses were performed by liquid and gas chromatography. The quality of coffee differs with unique sensorial profiles in growing environments corresponding to altitudes above 1100 m. Sensory descriptors, taste, acidity, body, and sweetness correspond to the growing environment and range depending on the processing method and color of the fruit. It was possible to discriminate the sensory quality of coffee processed by the wet method with mechanical removal of the skin and mucilage of fruits by analyzing the organic acids profile associated with the bioactives, caffeine, trigonelline and chlorogenic acids (3,4 and 5-CQA), determined in green coffee. It was not possible to discriminate the sensory quality of coffee from the fatty acid profile determined in the green coffee for the Yellow Bourbon and Acaiá genotypes by neither the wet nor the dry process.